CHAPTER XI 



BLOOD, LYMPH, AND CHYLE 



200. Function of the Blood. It will be remembered that 

 one of the essential properties of the living cell is its 

 power to incorporate into its own substance matter from 

 outside itself, a process which results in growth or in 

 repairing waste ; while another property, involved in 

 this, is the power to break down by oxidation, that is, to 

 resolve portions of its own body into simpler chemical 

 substances, thus producing waste matter. 



In order that this double process may go on continually 

 (as it must while the cell is living), oxygen and oxidizable 

 substances, that is, food, must be brought to each cell, and 

 provision must be made for removing the waste products. 

 The blood is the medium for accomplishing this. 



201. The Blood as a Tissue. Blood is classed, for valid 

 reasons, among the connective tissues. While it does not 

 furnish support to the body or its parts in the same sense 

 as do more solid connective tissues, such as bone or 

 cartilage, it does support the whole body by conveying 

 nutriment to every part. It is like other connective 

 tissues also in that the cells make up a comparatively 

 small portion of its substance, the* intercellular material 

 being largely in excess. And, finally, it is formed in the 

 development of the embryo from the same layer as^ are 

 the other connective tissues. 



MACY'S PHYS. 10 147 



